Macro rutie::unsafe_methods [−][src]
macro_rules! unsafe_methods { ( $itself_class: ty, $itself_name: ident, $( fn $method_name: ident ($($arg_name: ident: $arg_type: ty),*) -> $return_type: ty $body: block )* ) => { ... }; }
Creates unsafe callbacks for Ruby methods
This macro is unsafe, because:
- it uses automatic unsafe conversions for arguments (no guarantee that Ruby objects match the types which you expect);
- no bound checks for the array of provided arguments (no guarantee that all the expected arguments are provided);
That is why creating callbacks in unsafe way may cause panics.
Due to the same reasons unsafe callbacks are faster.
Use it when:
- you own the Ruby code which passes arguments to callback;
- you are sure that all the object has correct type;
- you are sure that all the required arguments are provided;
- Ruby code has a good test coverage.
Examples
#[macro_use] extern crate rutie; use rutie::{Boolean, Class, Fixnum, Object, RString, VM}; // Creates `string_length_equals` functions unsafe_methods!( RString, // type of `self` object itself, // name of `self` object which will be used in methods fn string_length_equals(expected_length: Fixnum) -> Boolean { let real_length = itself.to_str().len() as i64; Boolean::new(expected_length.to_i64() == real_length) } ); fn main() { Class::from_existing("String").define(|itself| { itself.def("length_equals?", string_length_equals); }); }
Ruby:
class String
def blank?
# ...
end
def length_equals?(expected_length)
# ...
end
end